Overview
- Scientists began tracking the Kelvin wave Monday and say it has already raised sea levels off Mexico; forecasts place its arrival along Southern California sometime between early and late October.
- NOAA and oceanographers estimate the wave can raise coastal water levels by roughly 6 to 12 inches and keep them elevated for months, creating a higher baseline for tides and waves.
- Southern California communities are already dealing with recent swell damage from Hurricane Marie that produced flooding, severe beach erosion and local emergency declarations in places such as Laguna Beach, Dana Point and Carlsbad.
- Researchers are now detecting and following the wave in near real time using satellite altimetry and moored buoys, giving emergency managers extra lead time to shore up seawalls, clear drainage and inspect vulnerable infrastructure.
- The key risk is compounding: the higher baseline will make ordinary swells, king tides and fall–winter storms much more likely to inundate homes, erode bluffs and threaten roads and rail, so residents and officials should prepare for months of elevated coastal threat.